One of my friends has a '64 Lincoln like mine (though his is buckskin tan, whereas mine is black) and he just took it out of winter storage. The problem is that the transmission will immediately downshift as soon as the accelerator pedal is touched. let off and it will go back into 2nd or 3rd, touch it even a little and it's back down. I thought that the kickdown linkage just needed to be tightened, but it seems that doing that would just cause the throttle to be partly open all the time and no real difference with the trans. Could it be that he just needs to find a much heavier spring for the kickdown bracket? That was my best guess since I remember the one on mine being pretty stout and his doesn't feel that heavy.

Okay, so, as soon as I posted that, I went out to my shed and immediately found a very heavy spring. I put it on his car, and now the problem is completely fixed. Apparently it shifts in all the right places unlike it ever has before. So...I suppose I'll leave this up in case anyone else has this problem.